This invention relates to the field of printer systems, more particularly to the printing of pixelated computer-generated text and images, still more particularly to the conversion of pixelated RGB-based image data into CMYK-based image data for printing.
Printing technology is undergoing a revolution as the inexpensive computational power developed for the desktop computer market is applied to the printing industry. Paralleling this growth are the skyrocketing expectations of consumers. While just a few short years ago the goal was to find an acceptable replacement for typewritten text, now the demand is for photographic quality reproduction of both scanned images and computer-generated graphics. Meeting this demand required a significant increase in the resolution of the printed imagesxe2x80x94both spatial resolution and color depthxe2x80x94that demanded the application of massive amounts of processing power and memory.
Additional demands are placed on the processing power of a printer system by the need to convert images from the Red-Green-Blue (RGB) format used by virtually all CRT-based computer displays to the Cyan-Magenta-Yellow-Black (CMYK) format used by most print engines.
Furthermore, while image quality continues to increase, consumers continue to demand higher and higher print speeds from today""s desktop printers. This expectation also leads to greater demands on the throughput of the print engine""s processor. Thus, there is a need in the art for systems and methods to increase the efficiency and throughput of print engines.
Objects and advantages will be obvious, and will in part appear hereinafter and will be accomplished by the present invention which provides system and method for efficient under color removal. One embodiment of the claimed invention provides a method of performing color space conversion and under color removal comprising the steps of providing an intensity word for a first, second, and third color for each of four pixels, subtracting each intensity word for the first, second, and third colors from a maximum intensity word to obtain an initial intensity word for a first, second, and third complementary color, comparing the first, second, and third complementary color initial intensity words for each pixel to determine a minimum color intensity word for each pixel, setting an initial combined color intensity word equal to the minimum color intensity word for each pixel, determining an output intensity word for each of the three complementary colors, each of the output intensity words for said complementary colors equal to the initial complementary color intensity word minus a scaled value of the initial combined color intensity word, each of the output intensity words for the complementary colors limited to a range bounded by a minimum and maximum producible intensity, and determining an output intensity word for the combined color, the output intensity word for the combined color equal to the initial combined color intensity word minus a scaled value of the initial combined color intensity word, the output intensity word for the combined color limited to a range bounded by a minimum and maximum producible intensity.